How does Facebook make money?

Facebook is the world's largest social network. Recently Facebook has reached a new milestone with mobile advertising generating 53% of it's revenue. This data comes from Facebook's recent earnings report, which shows a 23% increase from a year ago.

Facebook has been focusing on monetizing it's monthly active user base that use mobile, which now exceeds 1 billion people. Mobile has been a powerful opportunity for the social network.

Facebook’s ad revenues were up by more than 30% quarter-over-quarter according to it's Facebook Q4 and Full Year 2013 Earnings report.

• Revenue for the full year 2013 for Facebook was $7.87 billion, an increase of 55% year-over-year
• Daily active users (DAUs) were 757 million on average for December 2013, an increase of 22% year-over-year.
• Revenue from advertising was $2.34 billion in Q3 of 2013

Worldwide, advertising revenue per user was up from Q3 to Q4 of 2013 as well hitting $1.94.

SOURCE: https://investor.fb.com/results.cfm